1. Field of the Invention
The present invention relates to an electric connector that electrically connects circuit boards to each other.
2. Description of the Related Art
A floating connector that includes a plug and a socket and that can correct displacement between the plug and the socket relative to each other is known to date as an electric connector that maintains a connection between circuit boards regardless of an application of vibrations. Examples of electric connectors that have been developed to, particularly, highly reliably connect terminals to each other include an electric connector in which an S-shaped movable portion is provided on a socket terminal so that the socket is movable relative to the plug (Japanese Unexamined Patent Application Publication No. 2011-249076). Such an electric connector can maintain the plug and the socket in a correct fitting state due to the movable portion of the socket terminal absorbing vibrations that would occur when either the substrate on which the plug is mounted or the substrate on which the socket is mounted is displaced.
Some electric connectors, such as an electric connector used as a component of an automobile or a precision machine, are used in an environment subject to large impacts or vibrations. Although an electric connector used in such an environment can maintain the plug and the socket in a correct fitting state at the beginning, it may fail to maintain stable electrical connection due to an insufficient contact between the terminals upon receipt of an impact or vibrations during use. Examples of causes that make an electrical connection between the terminals unstable include impurities such as substrate residues or dust adhering to the plug terminal. A countermeasure for such impurities is essential to establish a highly reliable connection between terminals.